What model is your motherboard? Or did I miss that
Anyway I had a hell of a time using my Gigabyte motherboard until I flashed the BIOS.
These motherboards are currently reported to have issues with BAMT according to their HCL:
Gigabyte 890FXA-UD5 - Unable to boot from .img (BAMT and Debian Live image tested)
Gigabyte 990fxa-UD3 rev 1.0 - Unable to boot images with paritions? Doesn't work.